The present invention relates to a method according to the preamble of claim 1, a server according to the preamble of claim 8 and a communications node according to the preamble of claim 9.
Due to the deregulation of the telecommunications market, a subscriber, during the setup of a communications connection, can generally select from among communications paths of different telecommunications networks via which the communications connection to a communication partner can be set up. Selecting a code digit in addition to the subscriber number of the desired communications partner specifies a communications path in one of the telecommunications networks. The communications path can be selected, for example, based on where the lowest fees can be expected or based on where a desired transmission quality can be obtained. To be able to select a communications path based on the lowest fees one has to know what fees are being charged. Most recently, devices for private use have appeared on the market, which are inserted between a subscriber line of a telecommunications network and a subscriber terminal and which automatically establish the lowest cost communications connection to a communications partner. This feature is referred to as "least cost routing" and is available, for example, in many private telecommunications systems and in interface boxes that can be inserted between the subscriber line and a terminal. Such least cost routing devices have fee schedules stored in them, which the device uses to determine the respective fees and the code digit to be selected for different communications paths in order to set up the lowest cost communications connection. If the subscriber enters a subscriber number of a desired communications partner on his terminal, the terminal first transmits this subscriber number to the least cost routing device, which then determines the lowest cost communications path based on its fee schedule. The least cost routing device then sets up the desired communications connection by sending a call request with the code digit of the determined lowest cost communications path and the subscriber number of the desired communications partner to the subscriber line.
Many subscribers, however, do not have a least cost routing device. Consequently, such a subscriber will benefit from the lowest cost communications path only if he knows the fees of the possible communications paths and their respective code digits, determines the lowest cost communications path himself, and then enters the corresponding code digit in his terminal. Even the owner of a least cost routing device must put up with some inconvenience since the tariffs of the possible communications paths are frequently changed by their providers and the table stored in the least cost routing device must be updated with each tariff change. The owner must then inform himself of the tariffs in force and enter these tariffs in his least cost routing device.